King County Library System
Bellevue Regional Library, the largest library in the system
LocationKing County, Washington, US
TypePublic library
Size3.4 million items
Access and use
Access requirementsResidence in King County except the city of Seattle and the towns of Hunts Point and Yarrow Point
Circulation20.8 million
Population served1.4 million
Other information
Budget$120 million (2017)[1]
DirectorHeidi Daniel
References: Washington Public Library Statistical Report, 2016[2]

The King County Library System (KCLS) is a library system serving most residents of King County, Washington, United States. Headquartered in Issaquah, Washington, KCLS was the busiest library system in the United States as of 2010, circulating 22.4 million items.[3] It consists of 50 libraries, a Traveling Library Center, a mobile TechLab, and the ABC Express children’s library van. KCLS offers a collection of more than 4.1 million items, including books, periodicals, newspapers, audio and videotapes, films, CDs, DVDs and extensive online resources. All KCLS libraries offer free Wi-Fi connections. Patrons can check out 100 items at once and hold up to 50 items.


The library system began in 1942 when voters in King County established the King County Rural Library District in order to provide library services to people in rural areas with no easy access to city libraries. Funding for the library system is provided from property taxes. Funding measures for the system passed in 1966, 1977, 1980, 1988, 2002, 2004, and 2010.[4] Property taxes account for 94% of revenue today. The KCLS budget for 2017 was $120 million.[1] The name of the organization was changed from the King County Rural Library District to the present-day King County Library System in 1978, although the previous name of "Rural Library District" is still part of the organization's legal name.[5] The system received a $172 million capital bond in 2004 to rebuild, renovate, and expand most of its existing libraries, as well as building new libraries.

KCLS extends access privileges to residents of its service area, which includes all unincorporated areas of King County as well as residents of every city in the county except Hunts Point and Yarrow Point,[6] which do not offer any library service at all.[7] Residents of Seattle – which maintains its own library system – are allowed access to KCLS collections under reciprocal borrowing agreements between KCLS and Seattle's libraries.[8] KCLS also extends reciprocal borrowing privileges to residents of many other library systems in Western and North Central Washington. KCLS annexed Renton's public library system in 2010 following a vote by the city's residents.[9]

In 2011, KCLS won the Gale/Library Journal "Library of the Year" award.[3] The library eliminated its late fines in 2023 after finding it discouraged borrowing and cost more to collect and process. Replacement fees were instead levied for lost items.[10]


KCLS consists of 50 branches, the Traveling Library Center, ABC Express Vans, a mobile TechLab, and a service center located in Issaquah that houses the library's administrative offices. A program to build 17 new libraries and renovate or expand 26 other libraries was completed in 2019 with the opening of the Panther Lake Library in Kent.[11][12]


Mobile services

  • ABC Express
  • Traveling Library Center
  • Techlab
  • Library2Go


In 2016, KCLS circulated 20.8 million items, the third-most in the United States.[13]

KCLS is subscribed to OverDrive, an online service that offers digital e-book, audiobook, and magazine checkouts for library patrons. In 2023, the library system had 8.8 million digital checkouts—the third most of any system in OverDrive worldwide.[14]


  1. ^ a b "2017 Operating Budget" (PDF). King County Library System. Retrieved December 25, 2017.
  2. ^ "2016 Washington Public Library Statistical Report" (PDF). Washington State Library. October 2017. Retrieved December 25, 2017.
  3. ^ a b Berry, John, III (June 15, 2011). "Library of the Year 2011: King County Library System, WA". Library Journal. Retrieved June 18, 2011. Among the benchmarks was circulating 22.4 million items—more than any other library system in the United States—to the 1,318,745 people who live in King County.((cite news)): CS1 maint: multiple names: authors list (link)
  4. ^ "History". King County Library System. Retrieved January 5, 2018.
  5. ^ Becker, Paula (June 6, 2011). "King County Library System, Part 1". HistoryLink. Retrieved January 5, 2018.
  6. ^ "Areas Served by KCLS". King County Library System. July 16, 2012. Archived from the original on February 1, 2013. Retrieved January 5, 2018.
  7. ^ "Borrowing Outside of KCLS Service Areas". King County Library System. Archived from the original on May 10, 2012. Retrieved January 5, 2018.
  8. ^ "KCLS-SPL Reciprocal Use Borrowing Agreement". King County Library System. Archived from the original on May 22, 2012. Retrieved January 5, 2018.
  9. ^ Krishnan, Sonia (February 28, 2010). "Group tries to reverse Renton library vote". The Seattle Times. Retrieved March 1, 2010.
  10. ^ Zavala Magaña, Daisy (April 28, 2023). "King County libraries become latest to slash late fees". The Seattle Times. Retrieved January 21, 2024.
  11. ^ "KCLS Opens its 50th Library at the Kent Panther Lake Library Grand Opening Celebration" (Press release). King County Library System. March 13, 2019. Retrieved March 25, 2019.
  12. ^ Klaas, Mark (March 24, 2019). "Golden milestone: KCLS opens 50th library". Kent Reporter. Retrieved March 25, 2019.
  13. ^ "Library Statistics and Figures: The Nation's Largest Public Libraries". American Library Association. Retrieved January 21, 2024.
  14. ^ Blatchford, Taylor (January 19, 2024). "King County Library ranks third in the world for digital checkouts". The Seattle Times. Retrieved January 21, 2024.